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`To all whom it may concern.-

- Gr Gr is the fire-place..

' UNITE AS5.i.n'1'.ii 1.s. (PATENT OFFICE,

Jonnfnpennr, or `1 17Trs1s`unit` PA., Assienon rro MARGARET eaux.

jIMPROVEMENT'INCOATING SHEET-IRON WITH ZINC.

Specification forming part lof Lotters Patent N0.` 112,588, dated March y14, 1871.

`Be it-knownthat I, lJ OHN D. GREY, of Pittsburg,in the county of Allegheny and vState of Pennsylvania,have iiinvented a new and` Improved Process ofCo'ating Sheets of Iron; and

I dofhereby declare that the following is a full,

clear, and exact description. `of the same, reference being had `to the accompanying drawing, forming apart of this specification.

Myinvention relates to the art of coating sheets of iron with zincgfand @consists in the process hereinafter specified. f

I Williirst describe amechanisln by which my process maybe illustratedand exemplified,

Without designingto confine myself to `any particular means. v

The gure is a sectional view.

` A A are feed-rolls; `B B,`a series of pairs of yfriction guide-rolls;` laudC C, a pair of delivering and smoothingrolis. Dis a vessel containing the molten metal. E are ux-boxes,

l partially filled withjsal-ammoniac, and placed one atthe receiving andl the other at the delivery rolls.;` ."lhese boxesrare open at the bottoni, so that the sal-vammoniac may float on the molten metalfand`\.partially` envelop the surface of `one orbothoffthe rolls at each end.

F is a tube, located solas toforcc a current of air upon the` sheet; as it rises from the bath.

Thesheet of ironis passedinto the rolls at iiux in `box E, th`enthrough` the delivery-rolls,

and, finally, it `receives:the` cold air from tube M, impinged-directlyupon thecoated surface to fix the filmlontheiron.

y Underthe process"new` known to thepublic the sheet-iron is passed "down edgewise and vertically through the molten zinc, moved under and to :the other side of a partition, and then drawn up through sand. The sand prevents the oxidation of the 'soft film of zinc before it hasbeen xed and hardened on the iron.

, It Will-be perceived that I accomplish this very important object by the linx and smoothing delivery-rolls.` The result which I obtain is also a much smoothersurface.

Again, by the old method, the lsheet of ironv beingdipped, moved laterally under the par'- tition, ,and drawn up on the other side, it will be observed that `the end which rst passes toward the bottom comes up last, has therefore beenlonger exposed to the zinc, and is consequently covered with a heavier coat. This Want of `uniformity in the coating is very 0bjectionable, and is entirely remedied by my process, which exposes every part of the coat for exactly the same length of time.

The .obj ect ot' placing the linx so as to receive the sheet-iron after it passes through the feedrollsvisto remove thc acid which has been used to clean the surface of the sheet immediately beforethe sheet enters the molten zinc.

Having thus described all that is necessary toa full understanding of my invention, what I claim as new, and desire to secure by Letters Patent, is 4 The process of coating iron with a lilm of zincV bypassing sheets of the former through a ux of salammoniac,V then through the molten zinc, again through the same flux, then through smoothing-rolls, and, finally, impin ging thereon a current of cold air as it rises from the bath, all substantially as described.

- JOHN D. GREY.

Witnesses: SoLoN C. KEMON, Tuosrl). D. OURAND. 

